Three-phase combined type circuit breaker

Abstract

A three-phase combined type circuit breaker is disclosed which comprises a common housing, three-phase interrupting units in said common housing, movable contacts of the interrupting units connected through link mechanisms to operating devices for three phases respectively provided outside of the common housing, the switching operation thus being performed by phase. Rotary shafts are disposed in substantially the same plane in the link mechanisms. Each of the rotary shafts is provided with a connector for the movable contact, a connector for the operating device, and a sealing arrangement positioned between the two connectors for allowing the rotary shaft to rotate while holding the common housing in hermetic condition. This construction makes up a three-phase combined type circuit breaker capable of being operated by phase. The arrangement and construction of the three-phase rotary shafts simplifies maintenance and inspection of the interrupting units and the operating devices.

We claim: 
     
       1. A three-phase combined type circuit breaker comprising a common hermetic housing filled with an insulating medium, three-phase interrupting units each having a contact system independently operable within said hermetic housing, three phase operating devices operable independently of each other from outside of said hermetic housing, three-phase link mechanisms for connecting output terminals of said operating devices and operating force input terminals of said interrupting units by phase for operating said contact systems respectively, and three-phase hermetic alloy holding means arranged in a middle portion of each of said link mechanisms respectively for holding the hermetic condition of said hermetic housing while allowing the link mechanisms for respective phases to operate. 
     
     
       2. A three-phase combined type circuit breaker comprising a common housing filled with an insulating medium, interrupting units for three phases insulatively supported in said common housing and having a contact device with a selectively openable movable contact and a stationary contact, a mechanism case mechanically connected to said common housing and spacially communicated thereto, insulated operating rods for three phases each with an end connected to the movable contact of said contact device, rotary shafts for three phases each having an internal portion disposed within said mechanism case and provided with internal connecting means connected to the other end of the associated three-phase insulated operating rod and also having an external portion extending outside of said mechanism case through an opening thereof and provided with an outer connecting means, rotary seal means for three phases each provided in the opening of said mechanism case so as to provide hermetic seal between said mechanism case and the rotary shaft, while allowing said rotary shaft to rotate in said opening, and driving means for three phases operable independently of each other for operating said movable contacts through the rotation of said rotary shafts, said driving means being respectively connected to said outer connecting means of the rotary shafts for the three phases. 
     
     
       3. A three-phase combined type circuit breaker according to claim 2, wherein the rotary shafts for two phases among said rotary shafts for three phases are substantially aligned in a straight line, the outer connecting means for said two phases being disposed at respective end portions of said rotary shafts remote from each other, the rotary shafts for the other phase being arranged on an axis parallel to said straight line. 
     
     
       4. A three-phase combined type circuit breaker according to claim 2, wherein each of said driving means for three phases includes circuit opening drive means for supplying said rotary shaft with the turning effort making up the force for opening said movable contact, and closing drive means for supplying said rotary shaft with the turning effort making up the force for closing said movable contact, said insulated operating rod, said opening drive means and said closing drive means for each phase being connected to said rotary shaft in the directions of force transmission at intervals of 90 degrees with respect to each other. 
     
     
       5. A three-phase combined type circuit breaker according to claim 2, wherein said interrupting unit for each phase is arranged to operate vertically, and said rotary shaft for each phase is arranged substantially on a horizontal axis, and said driving means each comprises spring driving means for imparting a vertical force adapted to move the associated movable contact in one direction and hydraulic driving means for imparting a horizontal force adapted to move said associated movable contact in the other direction, said spring and hydraulic driving means being contained in a common control cubicle. 
     
     
       6. A three-phase combined type circuit breaker comprising a common housing filled with an insulating medium, interrupting units for three phases insulatively supported in said common housing and each having an openable movable contact and a stationary contact, a mechanism case mechanically connected and spacially communicated with said common housing, rotary shafts for three phases including an internal portion positioned within said mechanism case and an external portion positioned outside of said mechanism case, the rotary shafts for two phases being disposed substantially on the same axis, the rotary shaft for the other phase being disposed on an axis parallel thereto, internal connecting means for connecting the other end of each of said insulated operating rods for three phases to the internal portion of each of said rotary shafts, outer connecting means connected to the external portion of each of said rotary shafts, rotary seal means disposed between said two connecting means of said rotary shafts for allowing said rotary shafts for three phases to rotate while holding said common housing in hermetic condition, a second rotary shaft rotatably supported at a predetermined distance from said insulated operating rod of said rotary shaft of said other phase in opposed relation thereto, connecting means connected to said second rotary shaft, and driving means independently operated for each phase and connected to the outer connecting means respectively connected to said rotary shafts for two phases on the same axis on the one hand and to said connecting means connected to said second rotary shaft on the other hand, said driving means for each phase generating a driving force for operating said movable contact for each phase. 
     
     
       7. A three-phase combined type circuit breaker according to claim 6, wherein said two rotary shafts extend from inside to outside of said mechanism case in substantially opposite directions, each of said driving means for each phase including hydraulic driving means for generating an operating force for at least one of the opening and closing actions of said movable contact, said hydraulic driving means for three phases being arranged near the corners of an inverted triangle, the outputs of said hydraulic driving means for respective phase being connected to said outer connecting means of said rotary shafts for two phases on the same axis through link mechanisms respectively and also to said connecting means for the other phase. 
     
     
       8. A three-phase combined type circuit breaker according to claim 6, wherein said driving means for each phase comprises opening drive means for imparting an opening force for said movable contact and closing driving means for imparting a closing force for said movable contact, each of said two rotary shafts and said second rotary shaft has an L-shaped lever with an end thereof connected to said opening drive means and with the other end thereof connected to said closing drive means, and a pair of second levers coupled to the sides of said L-shaped lever, said circuit breaker further comprising dash pot devices for three phases each having a piston shaft connected to said second lever through a link. 
     
     
       9. A three-phase combined type circuit breaker according to claim 8, wherein said opening drive means, said closing drive means and said dash pot devices are arranged in substantially the same vertical plane in the operating directions at intervals of about 90 degrees from each other. 
     
     
       10. A three-phase combined type circuit breaker according to claim 1, wherein each of said three-phase link mechanisms has an end portion disposed in said housing and extending through an opening such that an opposite end portion is disposed outside of said housing, said opposite end portion of said link mechanisms being respectively connected to one of said operating devices so that when one of said operating devices is operated a corresponding one of said interrupting units is operated, and wherein said three-phase hermetic alloy holding means includes a sealing means mounted in the opening of said housing through which said link mechanisms extend for sealing the opening while allowing said link mechanisms to be independently operated. 
     
     
       11. A three-phase combined type circuit breaker according to claim 2, wherein said common housing defines a first space filled with said insulating medium, said interrupting units being insulatively supported in said first space, said mechanism case defining a second space, the end of the insulated operating rods connected to the movable contact device is disposed in said first space and an opposite end of each of the insulated operating rods is disposed in said second space, the internal portion of each of said rotary shafts is disposed in said second space, and wherein said driving means for the three phases is adapted to operate a connected one of said rotary shafts so that when one of said driving means is operated the rotary shaft connected thereto is rotated whereby one of said interrupting units is selectively operated. 
     
     
       12. A three-phase combined type circuit breaker according to claim 11, wherein each of said driving means comprises first and second driving means for separately applying first and second linear motion to the outer connecting means of the rotary shaft connected thereto, the second linear motion being in a direction substantially perpendicular to a direction of the first linear motion, said outer connecting means being adapted to convert said first linear motion into a rotary motion of said rotary shaft for opening the associated contact device and for converting the second linear motion into a rotary motion of said rotary shaft for closing said contact device. 
     
     
       13. A three-phase combined type circuit breaker according to claim 6, wherein the common housing includes a first space accommodating the insulating medium, said mechanism case defining a second space, insulated operating rods for the three phases are provided, each of said operating rods has an end portion disposed in said first space and operatively connected to the movable contact of a corresponding one of said interrupting units and a second end portion disposed in said second space, said rotary shafts being respectively connected to the second end portions of the insulated operating rods with the external portion of the respective rotary shafts extending through an opening in the mechanism case, said connecting means of said second rotary shaft is connected to said outer connecting means of said other of said rotary shafts for transmitting rotary movement of said second rotary shaft to said other of said rotary shafts, and wherein said driving means is adapted to move said movable contacts towards and away from said stationary contacts so as to selectively open and close the circuit breaker.